1. Field of the Invention
This invention relates to a method of making arched V-belts consisting primarily of polymeric material.
2. Prior Art Statement
It is known in the art to provide a method of making a plurality of polymeric arched V-belts comprising the steps of, defining an uncured belt sleeve having inside and outside surfaces, providing a metal forming member having a plurality of substantially identical axially aligned and annular metal forming surfaces of concave cross-sectional configuration, placing the uncured belt sleeve with its inside surface adjacent the metal forming surfaces, compressing the belt sleeve against the metal forming surfaces to thereby form annular arched portions in the sleeve with each of the arched portions corresponding roughly in configuration to a forming surface, curing the belt sleeve during the compressing step, cutting the cured belt sleeve to define a plurality of arched belts corresponding in number to the plurality of annular forming surfaces with each of the arched belts also corresponding roughly in configuration to a forming surface, and inverting each arched belt thus defined and as disclosed in U.S. Pat. No. 3,615,988.
However, although the method of U.S. Pat. No. 3,615,988 enables the production of arched polymeric V-belts which have been commercially successful, it has certain deficiencies, some of which will now be described. In particular, in using the method of this patent it is difficult to separate each cured belt sleeve from its concave metal forming surfaces and in some instances the cured sleeve has been damaged during removal resulting in unnecessary scrapping of portions of the cured sleeve and added belt costs. Also, with such method it is not commercially practical to make arched belts which use a load-carrying cord, in their associated belt sleeve, made of a material which has poor compressive strength, e.g., glass and aromatic polyamides, for example, inasmuch as the method requires such belt sleeve to be made in an inverted manner and during curing the load-carrying cord is subjected to compressive loads. Finally, the method of this patent teaches the use of a cylindrical rubber member, which has a comparatively thick wall, for the purpose of applying forming forces during curing and the thick wall thereof makes it difficult to define arched portions in the belt sleeve being cured in a precise manner.
It has been proposed in U.S. Pat. No. 4,106,966 to provide a method of making endless power transmission belts each having a toothed outside surface by building a belt sleeve on a drum, disposing a polymeric curing jacket having a toothed inside surface around the sleeve with the teeth of the jacket against the sleeve, curing the sleeve while applying pressure radially inwardly against the jacket so that the jacket defines a toothed outside surface on the sleeve during curing, and cutting the cured sleeve to define a plurality of belts each having a toothed outside surface.
It has also been proposed in U.S. Pat. No. 2,883,701 to provide a method of making a plurality of individual V-belts in a correct or right-side-out manner by applying a radially outwardly direct fluid pressure against uncured individual belt bodies through a comparatively thick walled flexible sleeve while subjecting the uncured belt bodies and supporting components to a curing environment.
Finally, it has been proposed in U.S. Pat. No. 3,964,846 to apply, during curing, a radially outwardly directed fluid pressure against an ordinary belt sleeve which may utilize a reinforcing member made of glass material and the radially outwardly directed pressure prevents compressive loads from being exerted against the glass material. The method of this latter patent also provides for the application of a lesser radially inwardly directed pressure against the sleeve during curing.
It is an object of this invention to provide an improved method of making a plurality of arched polymeric V-belts.
Other aspects, embodiments, objects, and advantages of this invention will become apparent from the following specification, claims, and drawings.